Methods and structures for forming and improving solder joint thickness and planarity control features for solar cells

ABSTRACT

A method for connecting a plurality of solar cells and an improved interconnect is disclosed. The method includes aligning an interconnect to a plurality of solar cells having solder pads, where the interconnect has a main body and tabs extending therefrom, and where each of the tabs has a downward depression, such that the tabs are positioned above the solder pads in between solar cells and pinning the interconnect against a work surface by pressing a hold down pin against the main body of the interconnect such that a lower surface of the interconnect tabs are maintained parallel to an upper surfaces of the solder pads, and such that the depression of each of the tabs flatly contacts the solder pads. The method can also include cantilevered tabs extending downwardly from the main body providing a controlled spring force between the tab lower surface and the solder pad upper surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority of U.S. Provisional PatentApplication No. 61/707,851, filed Sep. 28, 2012, entitled “METHODS ANDSTRUCTURES FOR FORMING AND IMPROVING SOLDER JOINT THICKNESS ANDPLANARITY CONTROL FEATURES FOR SOLAR CELLS,” the disclosure of which isincorporated by reference herein in its entirety and for all purposes.

TECHNICAL FIELD

Embodiments of the subject matter described herein relate generally tophotovoltaic assemblies including solar cells, photovoltaic modules andassociated electronic components. More particularly, one or moreembodiments of the present inventions relate to electrically connectinga plurality of solar cells in preparation for installation intophotovoltaic modules.

BACKGROUND

Solar cells are well known devices for converting solar radiation toelectrical energy. Several solar cells can be electrically connectedtogether using one or more interconnects to form a solar cell array. Thesolar cell array can be packaged into a photovoltaic (PV) module usingvarious processes and encapsulant materials.

Techniques for improving manufacturing processes related to electricallyconnecting solar cells are beneficial as these are intrinsic part of thestandard photovoltaic (PV) module fabrication process. Such techniquesmay prevent solar cell cracking during solder joint formation, preventcontamination from solder residue and improve the positioning accuracyof a solder joint on a solar cell.

BRIEF SUMMARY

An aspect of at least one of the inventions disclosed herein includesthe realization that although areas of thin-film solder electricallyconnecting interconnects with solar cells can fail due to the effects ofthermal fatigue or other mechanisms, failure rates can be reduced bymodifying the methods and/or hardware used to electrically connectinterconnects with solar cells. For example, in some known solar cellarrays, interconnects can be electrically connected to solar cells witha soldering techniques that results in a wedge-shaped solder layer, aportion of which is thin. Inspection of failed solar cell arrays hasrevealed that the failure of the solder layer appears to emanate fromthese thin areas of a wedge-shaped solder layer.

An aspect of the least one of the inventions disclosed herein includesthe realization that by forming a thicker solder layer around a thinsolder layer can help prevent the thin solder layer from failing. Forexample, by surrounding a thin solder layer with a thicker solder layer,growth of cracks that might emanate from the same solder layer can bereduced, slowed, or eliminated.

In accordance with at least one of the embodiments disclosed herein, amethod for connecting solar cells can include positioning a first solarcell adjacent to a second solar cell, each solar cell having a pluralityof solder pads. The method can also include aligning a firstinterconnect to the first and second solar cells where the firstinterconnect has a main body and tabs extending therefrom, and whereeach of the tabs has a downward depression, such that lower surfaces ofthe tabs are positioned above the upper surface of the solder pads ofboth the first and second solar cells. The method can also includepinning the first interconnect against a work surface by pressing a holddown pin against the main body of the first interconnect such that thelower surfaces of the interconnect tabs are maintained substantiallyparallel to the upper surfaces of the solder pads, and such that thedepression of each of the tabs substantially flatly contacts one of thesolder pads.

In some embodiments, a method for connecting solar cells can includeforming a solder paste into a liquid state uniformly spread around thedepression between the interconnect tabs and solder pads, therebyforming an electrical connection between the first and second solarcells. In another embodiment, the method can include allowing the solderpads on each solar cell to form in two rows along two opposite edges,each row of solder pads corresponds to and is electrically coupled tothe positive or negative electrode of the solar cell, and wherepositioning a first solar cell adjacent to a second solar cell includespositioning the solder pads of a first electrode of the first solar cellproximate to the solder pads of the opposite electrode of the secondsolar cell. In still another embodiment, positioning a first solar celladjacent to a second solar cell can include positioning the solder padsof the first solar cell proximate and perpendicular to the solder padsof the second solar cell.

In still another embodiment, positioning a first solar cell adjacent toa second solar cell can include positioning the solder pads of the firstsolar cell proximate and parallel to the solder pads of the second solarcell. In some embodiments, the method can further include depositingsolder paste on the plurality of solder pads prior to aligning the firstinterconnect to the first and second solar cells. In still anotherembodiment, the method can also include pre-applying the solder paste onthe lower surface of the interconnect tabs prior to aligning the firstinterconnect to the first and second solar cells.

In another embodiment, pinning the first interconnect against a worksurface allows for a contact force in the range of 0-1 Newtons betweenthe lower surface of the tab and the upper surface of the solder pad. Instill another embodiment, the method can further include positioning athird solar cell adjacent to the second solar cell, where a secondinterconnect is used to connect the third solar cell to the second solarcell, forming a plurality of electrically connected solar cells having afirst, second and third solar cell and a first and second interconnect.In yet another embodiment, the method can include any number of solarcells and interconnects to create a solar array of electricallyconnected solar cells.

Another method for connecting a plurality of solar cells can includepositioning a first solar cell adjacent to a second solar cell, eachsolar cell comprising a plurality of solder pads, where positioning afirst solar cell adjacent to a second solar cell includes positioningthe solder pads of the first solar cell proximate and perpendicular tothe solder pads of the second solar cell. The method can also includesaligning a first interconnect to the first and second solar cells, wherethe first interconnect has a main body and cantilevered tabs extendingdownwardly thereform, and wherein each of the tabs has a downwarddepression with a height in the range of 10-50 microns centrally locatednear a tab edge, such that lower surfaces of the tabs are positionedabove the upper surface of the solder pads of both the first and secondsolar cells. The method can further include pinning the firstinterconnect against a work surface by pressing a hold down pin againstthe main body of the first interconnect such that the lower surfaces ofthe interconnect tabs are maintained substantially parallel to the uppersurfaces of the solder pads, and such that the depression of each of thetabs substantially flatly contacts one of the solder pads. The methodcan further include forming a solder paste into a liquid state uniformlyspread around the depression between the interconnect tabs and solderpads thereby forming an electrical connection between the first andsecond solar cells. In some embodiments, forming a solder paste into aliquid state includes forming a solder paste into a liquid state usinginduction soldering. In other embodiments, the method can furtherinclude depositing solder paste on the plurality of solder pads prior toaligning the first interconnect to the first and second solar cells.

Still another method for connecting a plurality of solar cells caninclude positioning a first solar cell adjacent to a second solar cell,each solar cell having a plurality of solder pads, where positioning afirst solar cell adjacent to a second solar cell includes positioningthe solder pads of the first solar cell proximate and parallel to thesolder pads of the second solar cell. The method can also includealigning a first interconnect to the first and second solar cells, wherethe first interconnect has a main body and cantilevered tabs extendingdownwardly therefrom, and where each of the tabs has a downwarddepression with a height in the range of 10-50 microns centrally locatednear a tab edge, such that lower surfaces of the tabs are positionedabove the upper surface of the solder pads of both the first and secondsolar cells. The method can also include pinning the first interconnectagainst a work surface by pressing down against the main body of thefirst interconnect such that the lower surfaces of the interconnect tabsare maintained substantially parallel to the upper surfaces of thesolder pads, and such that the depression of each of the tabssubstantially flatly contacts one of the solder pads. The method canfurther include forming a solder paste into a liquid state uniformlyspread around the depression between the interconnect tabs and solderpads thereby forming an electrical connection between the first andsecond solar cells. In some embodiments, the method can include forminga solder paste into a liquid state including forming a solder paste intoa liquid state using hot soldering. In other embodiments, the method caninclude pre-applying the solder paste on the lower surface of theinterconnect tabs prior to aligning the first interconnect to the firstand second solar cells.

In some embodiments, a plurality of electrically connected solar cellscan include a first solar cell adjacent to a second solar cell, eachsolar cell having solder pads. The plurality of electrically connectedsolar cells can also include an interconnect aligned to the first andsecond solar cells, where the first interconnect has a main body and aplurality of tabs extending from the main body, and where each of thetabs have a downward depression, such that lower surfaces of the tabsare positioned above the upper surface of the solder pads of both thefirst and second solar cells. In some embodiments, the height of thedownward depression can be in the range of 10-50 microns. In otherembodiments, the thickness of the tab is in the range of 50-150 microns.In still other embodiments, the width of the tab is in the range of 2-10millimeters. In yet other embodiments, the length of the tab is in therange of 2-10 millimeters.

In some embodiments, the depression can be a depression selected fromthe group containing circular depression, oblong depression, triangulardepression, square depression, polygon depression, rectangulardepression, rounded-edge rectangular depression, dimple depression,partially hollowed depression, stamped out depression and concavedepression. In other embodiments, the interconnect tabs can becantilevered tabs extending downwardly from the main body of theinterconnect. In still other embodiments, the plurality tabs extend froma single side of the main body. In yet other embodiments, the solderpads on each solar cell are formed in two rows along two opposite edges,and each row of solder pads corresponds to and is electrically coupledto the positive or negative electrode of the solar cell, and where thesolder pads of a first electrode of the first solar cell is proximate tothe solder pads of the opposite electrode of the second solar cell.

In some embodiments, the solder pads of the first solar cell areproximate and parallel to the solder pads of the second solar cell. Inother embodiments, the solder pads of the first solar cell are proximateand perpendicular to the solder pads of the second solar cell. In stillother embodiments, a solder paste can be deposited on the upper surfacesof the solder pads of both first and second solar cells. In yet otherembodiments, a solder paste can be pre-applied on the lower surfaces ofthe interconnect tabs.

In some embodiments, the plurality of solar cells can be a plurality ofsolar cells selected from the group containing back-contact solar cells,front-contact solar cells, monocrystalline silicon solar cells,polycrystalline silicon solar cells, amorphous silicon solar cells, thinfilm silicon solar cells, copper indium gallium selenide (CIGS) solarcells, and cadmium telluride solar cells. In other embodiments, a thirdsolar cell can be connected to the second solar cell, where a secondinterconnect is used to connect the third solar cell to the second,forming a plurality of electrically connected solar cells having afirst, second and third solar cell and a first and second interconnect.

In accordance with yet another embodiment, a plurality of electricallyconnected solar cells can include a first solar cell adjacent to asecond solar cell, each solar cell having solder pads and where thesolder pads of the first solar cell are proximate and perpendicular tothe solder pads of the second solar cell. The plurality of electricallyconnected solar cells can include a first interconnect aligned to thefirst and second solar cells, where the first interconnect has a mainbody and a plurality of cantilevered tabs extending downwardly from themain body, where each of the tabs include a downward depression with aheight in the range of 10-50 microns centrally located near a tab edge,such that lower surfaces of the tabs are positioned above the uppersurface of the solder pads of both the first and second solar cells. Insome embodiments, a solder paste can be deposited on the upper surfacesof the solder pads of both first and second solar cells. In otherembodiments, the plurality of solar cells can be selected from the groupcontaining back-contact solar cells, front-contact solar cells,monocrystalline silicon solar cells, polycrystalline silicon solarcells, amorphous silicon solar cells, thin film silicon solar cells,copper indium gallium selenide (CIGS) solar cells, and cadmium telluridesolar cells.

In accordance with another embodiment, a plurality of electricallyconnected solar cells can include a first solar cell adjacent to asecond solar cell, each of the solar cells having solder pads and wherethe solder pads of the first solar cell are proximate and parallel tothe solder pads of the second solar cell. The plurality of electricallyconnected solar cells can also include a first interconnect aligned tothe first and second solar cells, where the first interconnect includesa main body and a plurality of cantilevered tabs extending downwardlyfrom a single side of the main body, where each of the tabs comprises adownward depression with a height in the range of 10-50 micronscentrally located near a tab edge, such that lower surfaces of the tabsare positioned above the upper surface of the solder pads of both thefirst and second solar cells. In some embodiments, a solder paste canpre-applied on the lower surfaces of the interconnect tabs. In otherembodiments, the plurality of solar cells can be selected from the groupcontaining back-contact solar cells, front-contact solar cells,monocrystalline silicon solar cells, polycrystalline silicon solarcells, amorphous silicon solar cells, thin film silicon solar cells,copper indium gallium selenide (CIGS) solar cells, and cadmium telluridesolar cells.

In other embodiments, a method for manufacturing an interconnect caninclude forming an interconnect having main body and a plurality of tabsusing a standard machining process. The method can also include stampingthe edges of the interconnect tabs to form downward depressions havingan upper surface within a recessed region and a lower surface on anextruding region of the tab. The method can also include applying solderpaste to the lower surface of the tabs. In some embodiments, the solderpaste can be screen printed onto the lower surface of the depression. Inother embodiments, subsequent to the application of solder paste on thelower surface of the depression, the tabs can be bent to formcantilevered tabs extending downwardly from the main body of the firstinterconnect. In still other embodiments, the depression can be formedinto a depression selected from the group containing circulardepression, oblong depression, triangular depression, square depression,polygon depression, rectangular depression, rounded-edge rectangulardepression, dimple depression, partially hollowed depression, stampedout depression and concave depression.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the subject matter may be derived byreferring to the detailed description and claims when considered inconjunction with the following figures, wherein like reference numbersrefer to similar elements throughout the figures.

FIG. 1 is a schematic cross-sectional representation of an automaticsolar cell stringer used in the standard operation for electricallyconnecting a plurality of solar cells;

FIG. 2 is an schematic plan view of a plurality of solar cells inaccordance with a standard process for electrically connecting aplurality of solar cells;

FIGS. 3 and 4 are schematic plan views of the plurality of solar cellsof FIG. 2 in accordance with the standard process for electricallyconnecting a plurality of solar cells;

FIG. 5 is a schematic perspective view of the plurality of solar cellsof FIG. 4 in accordance with the standard process for electricallyconnecting a plurality of solar cells;

FIGS. 6-8 are schematic cross-sectional representations of aninterconnect tab of FIGS. 2-5 in accordance with the standard processfor electrically connecting a plurality of solar cells;

FIG. 9 is an schematic plan view of a plurality electrically connectedsolar cells subsequent to the operations of FIGS. 2-8 in accordance withthe standard process for electrically connecting a plurality of solarcells;

FIGS. 10 and 11 are schematic plan views of a plurality of solar cellsin accordance with an embodiment;

FIG. 12 is a schematic perspective view of the plurality of solar cellsof FIG. 11 in accordance with an embodiment;

FIGS. 13-16 are schematic cross-sectional representations of aninterconnect tab of FIGS. 10-12 in accordance with an embodiment;

FIG. 17 a schematic plan view of a plurality electrically connectedsolar cells subsequent to the operations of FIGS. 10-16 in accordancewith an embodiment;

FIG. 18 is a schematic plan view of a plurality of solar cells inaccordance with another embodiment of the present inventions;

FIGS. 19 and 20 are schematic plan views of the plurality of solar cellsof FIG. 18 in accordance with another embodiment of the presentinventions;

FIG. 21 is a schematic perspective view of the plurality of solar cellsof FIG. 20 in accordance with another embodiment of the presentinventions;

FIGS. 22-25 are schematic cross-sectional representations of aninterconnect tab of FIGS. 18-21 in accordance with another embodiment;

FIG. 26 is a schematic plan view of a plurality electrically connectedsolar cells subsequent to the operations of FIGS. 18-25 in accordancewith another embodiment;

FIG. 27 is a schematic perspective view of an interconnect in accordancewith a standard process for electrically connecting a plurality of solarcells;

FIG. 28 is a schematic cross-sectional representations of theinterconnect of FIG. 27 in accordance with the standard process forelectrically connecting a plurality of solar cells;

FIG. 29 is a schematic perspective view of an interconnect forelectrically connecting a plurality of solar cells in accordance with anembodiment;

FIGS. 30 and 31 are schematic cross-sectional representations of theinterconnect of FIG. 29 in accordance with an embodiment;

FIG. 32 is a schematic plan view of an interconnect for electricallyconnecting solar cells in accordance with another embodiment;

FIG. 33 is a schematic plan view of an interconnect for electricallyconnecting solar cells in accordance with still another embodiment;

FIGS. 34 and 35 are schematic cross-sectional representations of theinterconnect of FIG. 33 in accordance with still another embodiment;

FIG. 36 is a schematic plan view of an interconnect for electricallyconnecting solar cells in accordance with yet another embodiment;

FIG. 37 is a schematic perspective view of different interconnect tabsfor electrically connecting solar cells in accordance with anembodiment; and

FIG. 38 is a cross-sectional representation of different interconnecttabs for electrically connecting solar cells in accordance with anembodiment;

FIGS. 39-42 are flowcharts illustrating methods of electricallyconnecting solar cells in accordance with an embodiment.

DETAILED DESCRIPTION

The following detailed description is merely illustrative in nature andis not intended to limit the embodiments of the subject matter or theapplication and uses of such embodiments. As used herein, the word“exemplary” means “serving as an example, instance, or illustration.”Any implementation described herein as exemplary is not necessarily tobe construed as preferred or advantageous over other implementations.Furthermore, there is no intention to be bound by any expressed orimplied theory presented in the preceding technical field, background,brief summary or the following detailed description.

In addition, certain terminology can also be used in the followingdescription for the purpose of reference only, and thus is not intendedto be limiting. For example, terms such as “upper”, “middle”, and“lower” refer to directions in the drawings to which reference is made.Terms such as “front” and “back” describe the orientation and/orlocation of portions of the component within a consistent but arbitraryframe of reference which is made clear by reference to the text and theassociated drawings describing the component under discussion. Suchterminology can include the words specifically mentioned above,derivatives thereof, and words of similar import. Similarly, the terms“first”, “second”, and other such numerical terms referring tostructures do not imply a sequence or order unless clearly indicated bythe context.

Methods, systems and hardware for connecting solar cells are disclosedbelow.

FIG. 1 illustrates a known automatic solar cell stringer used in astandard process of electrically connecting a plurality of solar cells.The automatic solar cell stringer 100 can include an enclosure 130 forhousing the different equipment required for electrically connecting aplurality of solar cells, a conveyor 132 for loading 131, processing andunloading 133 a plurality of solar cells, a solder paste applicator 134having dispenser tubes 136 used to dispense a solder paste 116 on afirst and second solar cell 102, 104, a vision inspection system 138 forinspecting the solder paste 116 integrity, a robotic arm 140 used toposition an interconnect 120 on the solder pads of a third and fourthsolar cells 105, 106, and a set of hold down pins 150 for pinning downan interconnect 120 to the solder pads of fifth and sixth solar cells107, 108, where the hold down pins 150 also include a solderingmechanism 152 to heat the solder paste 116 into a liquid state 117.During operation, and subsequent to a soldering process, the solderpaste 117 is allowed to cool down and form a solder joint 118. As aresult of processing using the above equipment, a plurality ofelectrically connected solar cells 110 are formed. The plurality ofsolar cells 110 can be unloaded 133 from the enclosure 130 by theconveyor 132.

FIGS. 2-5 illustrate operations in the standard process for electricallyconnecting a plurality of solar cells. The operation includespositioning a first solar cell 102 adjacent to a second solar cell 104,each solar cell having a plurality of positive solder pads 112 andnegative solder pads 114, where each of the solder pads 112, 114 areadapted to receive a solder paste 116. The plurality solar cells 103 canbe aligned using a camera and alignment chuck prior to the applicationof solder paste 116. The operation can also include placing aninterconnect 120 in alignment with the solder pads 112, 114 of first andsecond solar cells 102, 104. The interconnect 120 has a main body 122and tabs 124 positioned over the solder pads 112, 114 as shown in FIG.3. The operation can also include positioning a set of hold down pins150 above the tabs 124 in preparation for applying a contact force onthe tabs 124 as shown in FIGS. 4 and 5, where FIG. 5 depicts a schematicperspective view of FIG. 4.

FIGS. 6-8 illustrate cross-sectional representations of an interconnecttab in continuation of the standard process for electrically connectingthe plurality of solar cells. For clarity, only a single interconnecttab 120, second solar cell 104, hold down pin 150 and work surface 142are shown, where the operations discussed below are applicable to allsimilar structures mentioned above.

The operation can further include aligning a hold down pin 150 over aninterconnect tab 124, where the tab 124 has a lower surface 129positioned over a solder pad upper surface 119 of the second solar cell104. The solder paste 116 can be disposed between the tab lower surface129 and solder pad upper surface 119, where a working distance 190separates the lower surface 129 from the upper surface 119.

The operation can also include lowering the hold down pin in a downwarddirection 154, pinning the tab lower surface 129 onto the solder padupper surface 119. The hold down pin 150 can be used to conduct heat 156onto the solder paste 116 thereby heating the solder paste 116 to aliquid state 117. While the solder paste is in a liquid state 117, thecontact force from the hold down pin 150 can further pin theinterconnect tab lower surface 129 to the solder pad upper surface 119,where the tab 124 downwardly bends in a wedge contacting the solar cell104 as seen in FIG. 7.

The operation also includes allowing the solder paste 117 to cool,forming a solder joint 118. In some variations of the standard method ofoperation, forming the solder paste in a liquid state 117 is performedusing standard soldering processes. The contact force from the hold downpin 150 on the interconnect tab 124 is released by raising the hold downpin 150 in an upward direction 155 as shown in FIG. 8.

FIG. 9 illustrates a plurality of electrically connected solar cellssubsequent to performing the standard processes described in FIGS. 2-8.The plurality of electrically connected solar cells 110 includes a firstand second solar cell 102, 104, an interconnect 120 having a main body122 and tabs 124 electrically connecting both solar cells 102, 104through solder joints 118.

The standard method of electrically connecting solar cells discussedabove forms thin solder joints, and can result in a wedge-shaped solderjoint. With reference to FIGS. 7 and 8, the solder paste in a liquidstate 117 can flow unevenly between the lower surface 129 of the tab 124and the upper surface 119 of the solder pad 114 such that the solderjoint 118 formed can be a thin solder joint. A thin solder joint can beweak against mechanical strains, can have a short thermal fatigue lifeand thus be more frequently prone to failure as compared to uniformlyformed solder joints. Because solder paste has a relatively lowviscosity when molten it normally is not used alone as a structuraljoint.

It is also challenging for automatic solar cell stringers 100 mentionedabove to quickly process and hold parts with repeatable small tolerancesin gap and planarity during the standard process mentioned above. Sincethe hold down pin 150 acts directly on the interconnect tab 124 and overeach solder pads 112, 114, slight variation in the hold down pin 150contact force or alignment can lead to various defects.

If for example, the contact force from the hold down pin 150 is too low,spaces or bubbles in the solder paste 116, 117 may eventually formmicro-voids within the solder joint 118. Micro-voids can increase theresistance of a solder joint, decreasing the overall current collectedfrom a solar cell. A contact force that is too high could increase thecontact pressure on the solder pads 112, 114 resulting in cracking ofthe solder pads and damage the solar cell. Alternative techniquesinclude manual alignment between the hold down pin 150, interconnect tab120 and solder pad 112, 114. For narrower or smaller tabs however, theoperator may no longer be able to accurately and repeatedly position thehold down pin to the required tolerance, requiring advanced alignmenttools which are more costly.

Since the hold down pin 150 requires fine alignment control, delicateand controlled hold down forces and frequent cleaning of the pin tip,there is a need for improved solution to be used in photovoltaic (PV)module manufacturing. Alternative solutions can include modifying theautomation tool to maintain tight alignment, controlled contact forceand planarity of parts. This solution can result in a significantbottleneck in throughput and require complex handling mechanisms whichwould cost additional investment.

FIGS. 10-12 illustrate a method of electrically connecting a pluralityof solar cells. The method can include positioning a first solar cell202 adjacent to a second solar cell 204, each solar cell having aplurality of solder pads 212, 214 and positioning the solder pads 212 ofthe first solar cell 202 proximate and perpendicular to the solder pads214 of the second solar cell 204. The alignment of the first and secondsolar cells 202, 204 is similar to that of the alignment of the firstand second solar cells 102, 104 in the standard operation of FIG. 2.

The method can also include aligning a first interconnect 220 to thefirst and second solar cells 202, 204 where the first interconnect 220has a main body 222 and tabs 224 extending therefrom, and where each ofthe tabs has a downward depression 226, such that the tabs 224 arepositioned above the positive and negative solder pads 212, 214 of boththe first and second solar cells 202, 204 as seen in FIG. 10. The methodcan also include positioning a set of hold down pins 250 above the tabs224 in preparation to applying a contact force on the interconnect mainbody 222 as shown in FIGS. 11 and 12, where FIG. 12 depicts a schematicperspective view of FIG. 11.

With reference to FIGS. 13-16, there are shown cross-sectionalrepresentations of an interconnect tab in continuation of the method forelectrically connecting the plurality of solar cells of FIGS. 10-12.Similar to above, only a single interconnect tab 220, second solar cell204, hold down pin 250 and work surface 242 are shown, where theoperations discussed below are applicable to all similar structuresmentioned above.

The method can further include aligning a hold down pin 250 over theinterconnect main body 222, where a an interconnect tab lower surface229 is positioned parallel to the solder pad upper surface 219 of thesolar cell 204 as shown in FIG. 13. In some embodiments, theinterconnect tab can be slightly angled such as in FIG. 14, where theinterconnect tab is a cantilevered tab 225 extending downwardly from themain body of the first interconnect 220. A first working distance 280,282 can separate the main body 222 from the work surface 242 and asecond working distance 290, 292 can separate the tabs 224, 225 from thesolder pad upper surface 219.

The method can also include pinning the first interconnect 220 against awork surface 242 by lowering the hold down pin 250 in a downwarddirection 254, pressing the hold down pin 250 against the main body 222such that the tab lower surface 229 is maintained substantially parallelto the solder pad upper surface 219, and such that the depression 226substantially flatly contacts the solder pad upper surface 219 as shownin FIG. 15. The method can also includes using the hold down pin 250 toconduct heat 256 to form the solder paste 216 into a liquid state 217.

In some embodiments, the solder paste in a liquid state 217 can beformed using any standard soldering processes such as hot soldering orinduction soldering. While the solder paste is in a liquid state 217 thetab 224, 225 can be at a third working distance 294, where the contactforce from the hold down pin 250 can further allow the interconnect tab224, 225 to move downwardly toward the solar cell 204.

As shown in FIG. 15, as the lower surface 229 moves downwardly, thesolder paste 217 is squeezed outwardly, thereby forming a thickened areaaround the periphery of the lower surface 229. Using this process, thisthickened area of the solder paste 217 can be largely, substantially, orcontinuously in contact with the periphery of the much thinner portionof the solder paste 217 disposed directly between the lower surface 229and the upper surface 219 of the solar cell 204. As such, the resultingthickened solder, after cooling, can provide a source of material toflow into slip planes caused during fatigue-generated deformations,thereby inhibiting crack growth of the thin portion of the cooled solderlayer that is directly between the lower surface 229 and the uppersurface 219 of the solar cell 204. In embodiments where the recessedportion 226 is round at the lower surface 229, the thickened area ofsolder paste 217 can be roughly donut-shaped or toroidal. In otherembodiments where the lower surface 229 of the resource portion 226 asdifferent shapes, such as square, rectangular, star shaped, the liquidsolder paste 217 can flow around the contours associated with suchshapes so as to also produce a largely, substantially, or continuouslythickened area of solder paste 217 around the corresponding shape of thelower surface 229.

The method can also include allowing the solder paste 217 to cool down,forming a solder joint 218 similar to the above. The method can includereleasing the contact force between hold down pin 250 and theinterconnect main body 222 by raising the hold down pin 250 in an upwarddirection 255, where the tab 224, 225 is a fourth working distance 296away from the solder pad upper surface 219 as shown in FIG. 16.

In other embodiments, the interconnect tab 225 of FIG. 14 provides acontrolled spring force during the process when the main body 222 of theinterconnect 220 is pressed against the work surface 242 by the holddown pin 250 minimizing the third working distance. In still otherembodiments, the cantilever tab 225 provides a finer hold down force ascompared to the contact force from the hold down pin 150 of the standardmethod mentioned above, preventing cracking of the solder pad and damageto the solar cell 204. In yet other embodiments, reducing the size ofthe cantilever tab 225 can provide flexibility against contact stress onthe solder pad upper surface 219 also preventing solar cell cracking. Inother embodiments, pinning the hold down pin 250 against the main body222 of the interconnect 220 allows for a contact force in the range of0-1.0 Newtons between the tab lower surface 229 and the solder pad uppersurface 219. In still other embodiments, the depth of the downwarddepression 226 defines the solder meniscus, where the downwarddepression 226 controls the solder flux spread.

FIG. 17 illustrates a schematic perspective view of a plurality ofelectrically connected solar cells subsequent to performing the methodof FIGS. 10-16. The plurality of electrically connected solar cells 210includes a first and second solar cell 202, 204, an interconnect 220having a main body 222 and tabs 224 electrically connecting both solarcells 202, 204 through solder joints 218. In another embodiment,electrically connecting a plurality of solar cells 210 includeselectrically connecting a plurality of solar cells 210 selected from thegroup containing back-contact solar cells, front-contact solar cells,monocrystalline silicon solar cells, polycrystalline silicon solarcells, amorphous silicon solar cells, thin film silicon solar cells,copper indium gallium selenide (CIGS) solar cells, and cadmium telluridesolar cells.

With reference to FIGS. 18-21, there are shown additional methods ofelectrically connecting a plurality of solar cells. Some embodiments ofthese methods can include positioning a first solar cell 302 adjacent toa second solar cell 304, each solar cell having a plurality of positiveand negative solder pads 312, 214. The method can also includepositioning the solder pads 312 of the first solar cell 302 proximateand parallel to the solder pads 314 of the second solar cell 304. Insome embodiments, the plurality solar cells 303 can be aligned using acamera and alignment chuck prior to application of solder paste 316. Themethod can also include aligning a first interconnect 320 to the firstand second solar cells 302, 304, where the first interconnect has a mainbody 322 and cantilevered tabs 324, each of the tabs 324 having adownward depression 326 centrally located near a tab edge as seen inFIG. 19. The method can further include positioning a set of hold downpins 350 above the main body 322 in preparation to applying a contactforce on the main body 322 as shown in FIGS. 20 and 21, where FIG. 21depicts a schematic perspective view of FIG. 20.

FIGS. 22-25 illustrate cross-sectional representations of aninterconnect tab in continuation to the method of electricallyconnecting solar cells of FIGS. 18-21. Similar to above, only a singleinterconnect tab 320, second solar cell 304, hold down pin 350 and worksurface 342 are shown, where the operations discussed below areapplicable to all similar structures mentioned above. The method canfurther include aligning a hold down pin 350 over the interconnect mainbody 322, where an interconnect tab lower surface 329 is positionedparallel to a solder pad upper surface 319 as shown in FIG. 22. In someembodiments, the interconnect tab can be slightly angled such as in FIG.23, where the interconnect tab is a cantilevered tab 325 extendingdownwardly from the main body of the first interconnect 320. Asdiscussed above, a first working distance 380, 382 can separate the mainbody 322 from the work surface 342 and a second working distance 390,392 can separate the tabs 324, 325 from the solder pad upper surface319.

The method can also include pinning the first interconnect 320 against awork surface 342 by lowering the hold down pin 350 in a downwarddirection 354, pressing the hold down pin 350 against the main body 322such that the tab lower surface 329 is maintained substantially parallelto the solder pad upper surface 319, and such that the depression 326substantially flatly contacts the solder pad upper surface 219 as shownin FIG. 24. The method can also include using the hold down pin 350 toconduct heat 356 to melt a pre-formed solder paste 316 into a liquidstate 317.

In some embodiments similar to the above, the solder paste in a liquidstate 317 can be formed using any standard soldering processes such ashot soldering or induction soldering. While the solder paste is in aliquid state 317 the tab 224, 225 can be at a third working distance394, where the contact force from the hold down pin 350 can furtherallow downward depression 326 to come into contact with the solar cell204. The method can also include allowing the solder paste 317 to cooldown, forming a solder joint 318. The method can also include releasingthe contact force between hold down pin 350 and the interconnect mainbody 322 by raising the hold down pin 350 in an upward direction 355,where the tab 324, 325 is a fourth working distance 396 away from thesolder pad upper surface 319 as shown in FIG. 25.

In some embodiments, the interconnect tab 325 of FIG. 23 provides acontrolled spring force during the process when the main body 322 of theinterconnect 320 is pressed against the work surface 342 by the holddown pin 250 minimizing for the third working distance 394 similar toabove. In still other embodiments, the cantilever tab 325 provides afiner hold down force as compared to the contact force from the holddown pin 150 of the standard method mentioned above, preventing crackingof the solder pad and damage to the solar cell 304. In yet otherembodiments, reducing the size of the cantilever tab 325 can provideflexibility against contact stress on the solder pad upper surface 319also preventing solar cell cracking. In other embodiments, pinning thehold down pin 350 against the main body 322 of the interconnect 320allows for a contact force in the range of 0-1.0 Newtons between the tablower surface 329 and the solder pad upper surface 319. In still otherembodiments, the depth of the downward depression 326 defines the soldermeniscus, where the downward depression 326 controls the solder fluxspread.

FIG. 26 illustrates a schematic perspective view of a plurality ofelectrically connected solar cells subsequent to performing the methodof FIGS. 18-25. The plurality of electrically connected solar cells 310can include a first and second solar cell 302, 304, an interconnect 320having a main body 322 and tabs 324 electrically connecting both solarcells 302, 304 through solder joints 318. In other embodiments,connecting a plurality of solar cells 310 includes connecting aplurality of solar cells 310 selected from the group containingback-contact solar cells, front-contact solar cells, monocrystallinesilicon solar cells, polycrystalline silicon solar cells, amorphoussilicon solar cells, thin film silicon solar cells, copper indiumgallium selenide (CIGS) solar cells, and cadmium telluride solar cells.

With reference to FIGS. 27 and 28, there are shown an interconnect usedin the standard process of electrically connecting a plurality of solarcells. The interconnect 120 can include a main body 122 and a pluralityof tabs 124.

FIG. 29 illustrates an interconnect used in the method of electricallyconnecting a plurality of solar cells of FIGS. 2-17. In someembodiments, the interconnect can have a length 261 in the range of50-200 millimeters and a width 269 in the range of 5-20 millimeters. Inother embodiments, the interconnect can be made of a metal selected fromthe group containing copper, silver, gold and aluminum. In anembodiment, the interconnect can have a thin coating of nickel or tin.The interconnect 220 includes a main body 222 and a plurality of tabs224 extending from the main body, and where each of the tabs have adownward depression 226. In an embodiment, the width 260 of the tabs 224can be in the range of 2-10 millimeters and the length 262 of the tabcan be in the range of 2-10 millimeters. In other embodiments, thedistance between tabs 263 can be in the range of 5-50 millimeters.

With reference to FIGS. 30 and 31, there are shown cross-sectionalrepresentations of the interconnect tab of FIG. 29. FIG. 30 shows theinterconnect 220 with a tab 224 in accordance with the embodiment ofFIG. 13 and FIG. 31 shows the interconnect 220 with a tab 225 inaccordance with the embodiment of FIG. 14. In some embodiments, theinterconnect can have a thickness 268 in the range of 50-150 microns andthe interconnect tab can have a thickness 264 in the range of 50-150microns. In other embodiments, the width 267 of the depression can be inthe range of 2-10 millimeters. In still other embodiments, thedepression can have an upper cavity thickness 265 in the range of 10-50microns and a lower thickness 266 in the range of 10-50 microns.

FIG. 32 illustrates an embodiment of the interconnect from FIGS. 29-31.The interconnect 270 can have a main body 272, tabs 274, downwarddepressions 276 and relief features 278. In some environments, theinterconnect 270 can be an interconnect used in electrically connectingsolar cells manufactured by SunPower Corporation©. In other embodiments,the interconnect 270 can be used in electrically connecting plurality ofsolar cells selected from the group containing a back-contact solarcells, front-contact solar cells, monocrystalline silicon solar cells,polycrystalline silicon solar cells, amorphous silicon solar cells, thinfilm silicon solar cells, copper indium gallium selenide (CIGS) solarcells, and cadmium telluride solar cells.

With reference to FIG. 33, there is shown an interconnect used in themethod of electrically connecting a plurality of solar cells of FIG.18—In an embodiment, the interconnect 320 can have a length 361 in therange of 50-200 millimeters and a width 369 in the range of 8-20millimeters. In other embodiments, the interconnect 320 can be made of ametal selected from the group containing copper, silver, gold andaluminum. In an embodiment, the interconnect can have a thin coating ofnickel or tin. The interconnect 320 includes a main body 322 and aplurality of tabs 324 extending from the main body 322, and where eachof the tabs 324 have a downward depression 326.

In some embodiments, the width 360 of the tabs 324 can be in the rangeof 2-10 millimeters and the length 362 of the tab can be in the range of2-10 millimeters. In other embodiments, the distance between tabs 363can be in the range of 5-50 millimeters.

With reference to FIGS. 34 and 35, there are shown cross-sectionalrepresentations of the interconnect tab of FIG. 33. FIG. 30 shows theinterconnect 320 with a tab 324 in accordance with the embodiment ofFIG. 22 and FIG. 23 shows the interconnect 320 with a tab 325 inaccordance with the embodiment of FIG. 14. In some embodiments theinterconnect 320 can have a thickness 368 in the range of 50-150 micronsand the interconnect 320 tab 324 can have a thickness 364 in the rangeof 50-150 microns. In other embodiments, the width 367 of the depression326 can be in the range of 2-10 millimeters. In still other embodiments,the depression 326 can have an upper cavity thickness 365 in the rangeof 10-50 microns and a lower thickness 366 in the range of 10-50microns.

FIG. 36 illustrates an embodiment of the interconnect from FIGS. 33-35.The interconnect 370 can have a main body 372, tabs 374, 379, extrudingfeatures 375, downward depressions 376, relief features 377 andalignment features 378. In some embodiments, the interconnect 370 can bean interconnect used in electrically connecting solar cells manufacturedby SunPower Corporation©. In other embodiments, the interconnect 370 canbe used in electrically connecting plurality of solar cells selectedfrom the group containing a back-contact solar cells, front-contactsolar cells, monocrystalline silicon solar cells, polycrystallinesilicon solar cells, amorphous silicon solar cells, thin film siliconsolar cells, copper indium gallium selenide (CIGS) solar cells, andcadmium telluride solar cells.

FIG. 37 illustrates a schematic perspective view in accordance with anembodiment of the inventions discussed above. In some embodiments, thedownward depression 226, 326 can be a circular depression 400, oblongdepression 402, triangular depression 404, square depression 406,polygon depression 408, rectangular depression 410, and rounded-edgerectangular depression 412. In other embodiments the tabs 224, 324 mayhave instead an extrusion 414 on the lower surface of the tabs 224, 324as also seen below in 434 of FIG. 38.

With reference to FIG. 38, there are shown a cross-sectionalrepresentation of the plurality of downward depressions of FIG. 37. Insome embodiments, the downward depression 226, 326 can be a partiallyhollowed depression 420, regularly hollowed depression 422, dimpledepression 424, concave depression 426, square or rectangular depression428, partially hollowed rounded-edge rectangular depression 430, androunded-edge rectangular depression 432. In other embodiments the tabs224, 324 may have instead an extrusion 434 on the lower surface of thetabs 224, 324.

FIG. 39 illustrates a flow chart of an embodiment of a method forelectrically connecting a plurality of solar cells. As described above,the first operation 500 can include providing first and second solarcell 202, 204. The second operation 502 can include positioning thefirst solar cell 202 adjacent to the second solar cell 204, each solarcell having a plurality of solder pads 212, 214. The third operation 504can include aligning a first interconnect 220 to the first and secondsolar cells 202, 204, where the first interconnect 220 has a main body222 and tabs 224 extending therefrom, and where each of the tabs 224 hasa downward depression 226, such that lower surfaces 229 of the tabs 224are positioned above the upper surface 219 of the solder pads 212, 214of both the first and second solar cells 202, 204. The last operation506 can include pinning the first interconnect 220 against a worksurface 242 by pressing a hold down pin 250 against the main body 222 ofthe first interconnect 220 such that the lower surfaces 229 of theinterconnect tabs 224 are maintained substantially parallel to the uppersurfaces 219 of the solder pads 212, 214, and such that the depression226 of each of the tabs 224 substantially flatly contacts one of thesolder pads 212, 214. In some embodiments, the last operation 506 caninclude pressing down the main body 222 with sufficient force to causeliquid solder to flow outwardly from the lower surface of the depression226 toward a periphery of the depression 226 and so as to collect in asecond layer of solder around the periphery of the lower surface of thedepression 226.

With reference to FIG. 40, there is shown a flow chart of anotherembodiment for electrically connecting a plurality of solar cells. Thefirst operation 510 can include providing a first and second solar cell202, 204. The second operation 512 can include positioning the firstsolar cell 202 adjacent to the second solar cell 204, each solar cellhaving a plurality of solder pads 212, 214 formed in two rows along twoopposite edges, and each row of solder pads 212. 214 corresponds to andis electrically coupled to the positive or negative electrode of thesolar cell 202, 204, and where solder pads 212 of a first electrode ofthe first solar cell 202 are positioned proximate to the solder pads 214of the opposite electrode of the second solar cell 204. The thirdoperation 514 can include aligning a first interconnect 220 to the firstand second solar cells 202, 204, where the first interconnect 220 has amain body 222 and tabs 224 extending therefrom, and where each of thetabs 224 has a downward depression 226, such that lower surfaces 219 ofthe tabs 226 are positioned above the upper surface 319 of the solderpads 212, 214 of both the first and second solar cells 202, 204. Thefourth operation 516 can include pinning the first interconnect 220against a work surface 242 by pressing a hold down pin 250 against themain body 222 of the first interconnect 220 such that the lower surfaces229 of the interconnect tabs 224 are maintained substantially parallelto the upper surfaces 219 of the solder pads 212, 214, and such that thedepression of each of the tabs 224 substantially flatly contacts one ofthe solder pads 212, 214. The last operation 518 can include forming asolder paste 216 into a liquid state 217 uniformly spread around thedepression 226 between the interconnect tabs 224 and solder pads 212,214 thereby forming an electrical connection between the first andsecond solar cells 202, 204. Additionally, as noted above with regard tothe operation 506, the last operation 518 can include pressing down themain body 222 with sufficient force to cause liquid solder to flowoutwardly from the lower surface of the depression 226 toward aperiphery of the depression 226 and so as to collect in a second layerof solder around the periphery of the lower surface of the depression226.

FIG. 41 illustrates a flow chart of still another embodiment forelectrically connecting a plurality of solar cells. As discussed above,the first operation 520 can include providing a first and second solarcell 202, 204. The second operation 522 can include positioning a firstsolar cell 202 adjacent to a second solar cell 204, each solar cellhaving a plurality of solder pads 212, 214, where the solder pads 212,of the first solar cell 202 are positioned proximate and perpendicularto the solder pads 214 of the second solar cell 204. The third operation524 can include aligning a first interconnect 220 to the first andsecond solar cells 202, 204, where the first interconnect 220 has a mainbody 222 and cantilevered tabs 225 extending downwardly therefrom, andwhere each of the tabs 225 has a downward depression 226 with a heightin the range of 10-50 microns centrally located near a tab 225 edge,such that lower surfaces 229 of the tabs 225 are positioned above theupper surface 219 of the solder pads 212, 214 of both the first andsecond solar cells. The fourth operation 526 can include pinning thefirst interconnect 220 against a work surface 242 by pressing downagainst the main body 222 of the first interconnect 220 such that thelower surfaces 229 of the interconnect tabs 225 maintained substantiallyparallel to the upper surfaces 219 of the solder pads 212, 214, and suchthat the depression 226 of each of the tabs 225 substantially flatlycontacts one of the solder pads 212, 214. The last operation 528 caninclude forming a solder paste 217 into a liquid state uniformly spreadaround the depression 226 between the interconnect tabs 225 and solderpads 212, 214 thereby forming an electrical connection between the firstand second solar cells 202, 204. In an embodiment the cantilevered tabs225 can instead be the interconnect tabs 224 discussed above.Additionally, as noted above with regard to the operation 506, the lastoperation 528 can include pressing down the main body 222 withsufficient force to cause liquid solder to flow outwardly from the lowersurface of the depression 226 toward a periphery of the depression 226and so as to collect in a second layer of solder around the periphery ofthe lower surface of the depression 226.

With reference to FIG. 42, there is shown a flow chart of yet anotherembodiment for electrically connecting a plurality of solar cells. Thefirst operation 530 can include providing a first and second solar cell302, 304. The second operation 532 can include positioning a first solarcell 302 adjacent to a second solar cell 304, each solar cell having aplurality of solder pads 312, 314, where the solder pads 312 of thefirst solar cell 302 are positioned proximate and parallel to the solderpads 314 of the second solar cell 304. The third operation 534 caninclude aligning a first interconnect 320 to the first and second solarcells 302, 304, where the first interconnect 320 has a main body 322 andcantilevered tabs 325 extending downward thereform, and where each ofthe tabs 325 has a downward depression 326 with a height in the range of10-50 microns centrally located near a tab edge, such that lowersurfaces 329 of the tabs 325 are positioned above the upper surface 319of the solder pads 312, 314 of both the first and second solar cells302, 304. The fourth operation 534 can include pinning the firstinterconnect 320 against a work 342 surface by pressing a hold down pin350 against the main body 322 of the first interconnect 320 such thatthe lower surfaces 329 of the interconnect tabs 325 are maintainedsubstantially parallel to the upper surfaces 319 of the solder pads 312,314, and such that the depression 226 of each of the tabs 325substantially flatly contacts one of the solder pads 312, 314. The lastoperation 538 can include forming a solder paste into a liquid state 317uniformly spread around the depression 326 between the interconnect tabs325 and solder pads 312, 314 thereby forming an electrical connectionbetween the first and second solar cells 302, 304. In an embodiment, thecantilevered tabs 325 can instead be the interconnect tabs 324 discussedabove. Additionally, as noted above with regard to the operation 506,the last operation 538 can include pressing down the main body 222 withsufficient force to cause liquid solder to flow outwardly from the lowersurface of the depression 226 toward a periphery of the depression 226and so as to collect in a second layer of solder around the periphery ofthe lower surface of the depression 226.

While at least one exemplary embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexemplary embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the claimed subjectmatter in any way. Rather, the foregoing detailed description willprovide those skilled in the art with a convenient road map forimplementing the described embodiment or embodiments. It should beunderstood that various changes can be made in the function andarrangement of elements without departing from the scope defined by theclaims, which includes known equivalents and foreseeable equivalents atthe time of filing this patent application.

What is claimed is:
 1. A method for connecting a plurality of solarcells, the method comprising: positioning a first solar cell adjacent toa second solar cell, each solar cell comprising a plurality of solderpads; aligning a first interconnect to the first and second solar cells,wherein the first interconnect has a main body and tabs extendingtherefrom, and wherein each of the tabs has a downward depression, suchthat lower surfaces of the tabs are positioned above the upper surfaceof the solder pads of both the first and second solar cells; and pinningthe first interconnect against a work surface by pressing a hold downpin against the main body of the first interconnect such that the lowersurfaces of the interconnect tabs are maintained substantially parallelto the upper surfaces of the solder pads, and such that the depressionof each of the tabs substantially flatly contacts one of the solderpads.
 2. The method of claim 1, further comprising: forming a layer ofsolder paste into a liquid state uniformly spread around a periphery ofthe depression between the interconnect tabs and solder pads, therebyforming an electrical connection between the first and second solarcells.
 3. The method of claim 1, wherein the solder pads on each solarcell are formed in two rows along two opposite edges, and each row ofsolder pads corresponds to and is electrically coupled to the positiveor negative electrode of the solar cell, and wherein positioning a firstsolar cell adjacent to a second solar cell comprises positioning thesolder pads of a first electrode of the first solar cell proximate tothe solder pads of the opposite electrode of the second solar cell. 4.The method of claim 1, wherein positioning a first solar cell adjacentto a second solar cell comprises positioning the solder pads of thefirst solar cell proximate and parallel to the solder pads of the secondsolar cell.
 5. The method of claim 1, wherein positioning a first solarcell adjacent to a second solar cell comprises positioning the solderpads of the first solar cell proximate and perpendicular to the solderpads of the second solar cell.
 6. The method of claim 1, wherein theheight of the downward depression is in the range of 10-50 microns. 7.The method of claim 1, wherein connecting a plurality of solar cellscomprises connecting a plurality of solar cells selected from the groupcontaining back-contact solar cells, front-contact solar cells,monocrystalline silicon solar cells, polycrystalline silicon solarcells, amorphous silicon solar cells, thin film silicon solar cells,copper indium gallium selenide (CIGS) solar cells, and cadmium telluridesolar cells.
 8. The method of claim 1, further comprising depositingsolder paste on the plurality of solder pads prior to aligning the firstinterconnect to the first and second solar cells.
 9. The method of claim1, further comprising pre-applying the solder paste on the lower surfaceof the interconnect tabs prior to aligning the first interconnect to thefirst and second solar cells.
 10. The method of claim 1, wherein thedepression comprises a depression selected from the group containingcircular depression, oblong depression, triangular depression, squaredepression, polygon depression, rectangular depression, rounded-edgerectangular depression, dimple depression, partially holloweddepression, stamped out depression and concave depression.
 11. Themethod of claim 1, wherein the interconnect tabs comprise cantileveredtabs extending downwardly from the main body of the interconnect. 12.The method of claim 1, wherein pinning the first interconnect against awork surface allows for a contact force in the range of 0-1 Newtonsbetween the lower surface of the tab and the upper surface of the solderpad.
 13. A method for connecting a plurality of solar cells, the methodcomprising: positioning a first solar cell adjacent to a second solarcell, each solar cell comprising a plurality of solder pads, whereinpositioning a first solar cell adjacent to a second solar cell comprisespositioning the solder pads of the first solar cell proximate andperpendicular to the solder pads of the second solar cell; aligning afirst interconnect to the first and second solar cells, wherein thefirst interconnect has a main body and cantilevered tabs extendingdownwardly therefrom, and wherein each of the tabs has a downwarddepression with a height in the range of 10-50 microns centrally locatednear a tab edge, such that lower surfaces of the tabs are positionedabove the upper surface of the solder pads of both the first and secondsolar cells; pinning the first interconnect against a work surface bypressing down against the main body of the first interconnect such thatthe lower surfaces of the interconnect tabs maintained substantiallyparallel to the upper surfaces of the solder pads, and such that thedepression of each of the tabs substantially flatly contacts one of thesolder pads; and forming a layer of solder paste into a liquid stateuniformly spread around a periphery of the depression between theinterconnect tabs and solder pads thereby forming an electricalconnection between the first and second solar cells.
 14. The method ofclaim 13, wherein forming a solder paste into a liquid state comprisesforming a solder paste into a liquid state using induction soldering.15. The method of claim 13, further comprising depositing solder pasteon the plurality of solder pads prior to aligning the first interconnectto the first and second solar cells.
 16. The method of claim 13, whereinconnecting a plurality of solar cells comprises connecting a pluralityof solar cells selected from the group containing a back-contact solarcells, front-contact solar cells, monocrystalline silicon solar cells,polycrystalline silicon solar cells, amorphous silicon solar cells, thinfilm silicon solar cells, copper indium gallium selenide (CIGS) solarcells, and cadmium telluride solar cells.
 17. A method for connecting aplurality of solar cells, the method comprising: positioning a firstsolar cell adjacent to a second solar cell, each solar cell comprising aplurality of solder pads, wherein positioning a first solar celladjacent to a second solar cell comprises positioning the solder pads ofthe first solar cell proximate and parallel to the solder pads of thesecond solar cell; aligning a first interconnect to the first and secondsolar cells, wherein the first interconnect has a main body andcantilevered tabs extending downward thereform, and wherein each of thetabs has a downward depression with a height in the range of 10-50microns centrally located near a tab edge, such that lower surfaces ofthe tabs are positioned above the upper surface of the solder pads ofboth the first and second solar cells; pinning the first interconnectagainst a work surface by pressing a hold down pin against the main bodyof the first interconnect such that the lower surfaces of theinterconnect tabs are maintained substantially parallel to the uppersurfaces of the solder pads, and such that the depression of each of thetabs substantially flatly contacts one of the solder pads; and forming alayer of solder paste into a liquid state uniformly spread around aperiphery of the depression between the interconnect tabs and solderpads thereby forming an electrical connection between the first andsecond solar cells.
 18. The method of claim 17, wherein forming a solderpaste into a liquid state comprises forming a solder paste into a liquidstate using hot soldering.
 19. The method of claim 17, furthercomprising pre-applying the solder paste on the lower surface of theinterconnect tabs prior to aligning the first interconnect to the firstand second solar cells.
 20. The method of claim 17, wherein connecting aplurality of solar cells comprises connecting a plurality of solar cellsselected from the group containing a back-contact solar cells,front-contact solar cells, monocrystalline silicon solar cells,polycrystalline silicon solar cells, amorphous silicon solar cells, thinfilm silicon solar cells, copper indium gallium selenide (CIGS) solarcells, and cadmium telluride solar cells.